The 438-day figure requires some explanation, because early reports of Alvarenga’s arrival cited different durations — some said thirteen months, some said fifteen months, some said more than a year. The discrepancy arose partly from the difficulty of converting a drift that ran from mid-November 2012 to late January 2014 into a clean number of months (it is approximately fourteen and a half months), and partly from the fact that the exact departure date required reconciliation against official Mexican records, which the journalist Franklin undertook in the course of his research. The 438-day figure, which Franklin documented in detail, is the reconstructed duration based on the confirmed departure date and confirmed arrival date.
## The Diet That Kept Him Alive: Raw, Improvised, Sufficient
The question that medical experts focused on most intently when Alvarenga’s story broke was: how did he avoid scurvy?
Scurvy — vitamin C deficiency — is the disease that historically devastated long-distance sailors who couldn’t get fresh fruit or vegetables. It causes progressive deterioration of connective tissue, bleeding gums, weakness, and eventually death. British sailors of the age of sail were notoriously vulnerable to it. The standard assumption about a castaway subsisting on raw animal protein for more than a year was that scurvy would be a serious concern.
The answer, according to Claude Piantadosi, a professor at Duke University’s medical school who commented on the case, is that birds and turtles are fundamentally different from preserved meat in their vitamin C content. Unlike humans, birds and turtles synthesize their own vitamin C. This means that fresh bird and turtle meat — particularly the livers, which concentrate vitamin C — provides a meaningful supply of the vitamin. Historical sailors got scurvy not from eating meat per se, but from eating preserved meat, which loses its vitamin C through the oxidation that occurs during preservation. Alvarenga was eating his food raw and fresh, essentially immediately after killing it. Michael Tipton of the University of Portsmouth added that fish eyes are rich in vitamin C — another source that Alvarenga, as an experienced fisherman familiar with what a fish’s body contains, would have known to use.